The study is a multifacetted program consisting of four projects designed to increase our understanding of the monoclonal gammopathies. The projects and the program will increase our knowledge of the relationship between conditions associated with the monoclonal gammopathies; the mechanism of immunodeficiency in multiple myeloma; study of cell kinetics in patients with monoclonal gammopathies; and treatment of multiple myeloma bone disease with fluoride, calcium and vitamin D. These studies will provide information on this group of patients which is presently unavailable and may allow formulation of a more unified concept of these disorders.